Dealership says engine knocking means I need a new engine. I have put 3000 miles since last dealership visit. No change in engine. Could this be a catalytic converter or other problem? Do not hear the noise at 70 mph only at 0-40 mph.
What is the odometer reading? What warning lights are on? Have you tried using 91 octane fuel to see if that has any impact on the noise? Does the noise occur only when you are accelerating, or does it occur even if you are maintaining a steady speed of 30 mph on a level road? A defective catalytic converter typically will cause the engine ECU to log DTC P0420 and the check engine light will appear.
